1. Field of the Invention
This invention relates to exercise devices and, in particular, this invention relates to devices for exercising a user's abdominal muscles.
2. Background
During muscle training, it is difficult to isolate abdominal muscles from the hip flexors so as to achieve maximal overload and lower back health. A common solution of the prior art is avoiding hip flexion, or sit-ups, by performing only foreword spinal flexion, or by crunches. However, this practice is only marginally effective because eliminating movement in the hip joint does not inhibit the hip flexors. It is well accepted that a muscle contraction in the abdominal muscles will cause a corresponding contraction of adjacent muscles or the hip flexors. (Sherrington's Law of Irradiation) Persons with weak abdominal muscles rely on their hip flexors, even when performing crunches. The stronger hip flexors are recruited first. These hip flexors pull on the lumbar spine causing the back to hyperextend if the trainee's abdominal muscles are not strong enough to counterbalance this pull. Previous attempts to solve the problem of abdominal isolation involved making the crunch stricter. However, none of these approaches has effectively enabled an exercising person to effectively isolate his or her abdominal muscles because they have not addressed the neurological aspect of the problem of abdominal isolation. Moreover, none of these devices has indicated to a person that incorrect technique is being used during an exercise experience.